Relay construction and parts therefor or the like

ABSTRACT

A relay construction having a flexible diaphragm for balancing a poppet valve member thereof under certain conditions of operation of the relay construction so that the relay construction is adapted to automatically act as a normally closed relay, as a normally open relay or as a diverting relay depending upon where the fluid source and other devices are interconnected to the ports of the relay construction, the flexible diaphragm balancing the poppet valve member only when the relay construction is acting as a normally open relay or as a diverting relay.

United States Patent 11 1 1 1 3,857,411

Moon, Jr. Dec. 31, 1974 4] RELAY CONSTRUCTION AND PARTS 3,252,471 5/1966 OiSOn 137/85 T HE u E 3,604,460 9/1971 Delrue 137/112 x HEREFOR OR T K 3,653,408 4/1972 Coiner 235/20] ME X [75] Inventor: William T. Moon, Jr., Knoxville,

Tenn- Primary ExaminerRobert G. Nilson 73 Assignee; Robertshaw m Company, Attorney, Agent, or FirmCand0r, Candor & Tassone Richmond, Va. 22 Filed: June 27, 1973 [57] ABSTRACT A relay construction having a flexible diaphragm for balancing a poppet valve member thereof under certain conditions of operation of the relay construction [21] App]. No.: 373,941

[52] U S C 137/6275 137/112 13759 13 so that the relay construction is adapted to automati- 235/201 ME cally act as a normally closed relay, as a normally [51] Int. Cl. Fl6k 11/14 p relay or as a diverting lrelay depending p 53] Fi f Search 137/59 13 35 12 275; where the fluid source and other devices are intercon- 235 2 1 ME nected to the ports of the relay construction, the flexible diaphragm balancing the poppet valve member [56] References Cit d only when the relay construction is acting as a nor- UNITED STATES PATENTS mally open relay or as a diverting relay. 2,940,798 6/1960 Weber 137/627.5 ux 2 i 1 r ing ig es 535 VENT 2O CONTROL SUPPLY 5 SUPPLY NORM ALLY 01.03150 50 34 1 86 CONTROL SIGNAL 87 'OFF" 39 VENT 4O 32 47 79 83 8| NORMALLY OPEN PATENTED UEEB 1 I974 SHEET 10$ 3 PATENTEU 4 SHEET 20F 3 85 VENT CONTROL S l GNA l OFF 84 73 39 6| S/UPPLY 4| 76 FIG. 5 35 NORMALLY CLOSED 85 CONTROL 29 4 73 6| a SUPPLY 76 1 82 83 FIG.6

PPLY NORMALLY CLOSED 85 CONTROL @L ENT AL I F" RELAY CONSTRUCTION AND PARTS THEREFOR OR THE LIKE This invention relates to an improved relay construction as well as to improved parts for such a relay construction or the like.

It is well known that relay constructions have been provided wherein each has a particular operating function. For example, relay constructions have been provided that will each act as normally closed relay wherein fluid from a source is not interconnected by the particular normally closed relay to a fluid operated control device unless a fluid signal is directed to such relay construction. Similarly, normally open relay constructions have been provided where each interconnects the fluid source to the fluid operated control device only when a fluid signal is not being received by the particular relay construction. Also, relay constructions have been provided where each provides a diverting function such as where the particular relay construction will direct the source of fluid to only one fluid operated control device when the relay construction is not receiving a fluid signal and will direct the fluid source to only another fluid operated control device when the relay construction is receiving a fluid signal.

It is a feature of this invention to provide a single relay construction for providing the function of a normally closed relay, a normally open relay and a diverting relay so that the single relay construction can be utilized to function selectively as a normally closed relay, as a normally open relay or as a diverting relay.

Another feature of this invention is to provide such a relay construction wherein the relay construction will automatically act as a normally closed relay, as a normally open relay or as a diverting relay at the selection of the operator without changing the parts of the relay construction.

Another feature of this invention is to provide a relay construction that has a balanced poppet valve member therein.

In particular, one embodiment of this invention provides a relay construction having a housing provided with port means and with passage means and valve means interconnected with the port means. The housing has control means therein for causing the relay construction to selectively act as a normally closed relay, as a normally open relay or as a diverting relay. Such control means comprises a balancing means for a movable valve member of the valve means, the balancing means being adapted to balance the valve member only when the relay construction is acting as a normally open relay or as a diverting relay whereas when the relay is acting as a normally closed relay, the balancing means does not act on the valve member.

Accordingly, it is an object of this invention to provide an improved relay construction having one or more of the novel features set forth above or hereinafter shown or described.

Another object of this invention is to provide improved parts for such a relay construction or the like.

Other objects, uses and advantages of this invention are apparent from a reading of this description, which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIG. 1 is a cross-sectional view of the improved relay construction of this invention.

FIG. 2 is a reduced bottom view of the relay construction of FIG. 1.-

FIG. 3 is a reduced cross-sectional view taken on line 3-3 of FIG. 1.

FIG. 4 is a reduced, fragmentary, exploded perspective view illustrating certain parts at the bottom of the relay construction of FIG. 1. FIG. 5 is a reduced view similar to FIG. 1 and illustrates the relay construction when acting as a normally closed relay and with the signal means thereof in an off condition.

FIG. 6 is a view similar to FIG. 5 and illustrates the relay construction acting as a normally closed relay with the signal means in an on condition.

FIG. 7 is a view similar to FIG. 5 and illustrates the relay construction acting as a normally open relay with the signal means in an off condition.

FIG. 8 is a view similar to FIG. 7 and illustrates the relay construction acting as a normally open relay with the signal means in an on condition.

FIG. 9 is a view similar to FIG. 8 and illustrates the relay construction acting as a diverting relay with the signal means in an of condition.

FIG. 10 is a view similar to FIG. 9 and illustrates the relay construction acting as a diverting relay with the signal means in an on condition.

While the various features of this invention are hereinafter described and illustrated as providing a relay construction for acting as a normally closed relay, as a normally open relay or as a diverting relay, it is to be understood that the various features of this invention can be utilized singly or in any combination therof to provide other types of relay constructions if desired.

Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIG. 1, the improved relay construction of this invention is generally indicated by the reference numeral 20 and comprises a housing means 21 formed from a plurality of parts disposed in stacked aligned relation and being suitably secured together by conventional threaded fastening means 22.

For example, the housing means 21 can comprise a plurality of parts 23, 24, 25, 26 and 27 disposed in stacked aligned relation with flexible gasket or diaphragm sealing means 28, 29, 30 and 31 respectively disposed therebetween as illustrated to fluid seal the parts 23-27 together when the same are secured together by the fastening means 22.

The housing means 21 of the relay construction 20 is provided with five ports 32, 33, 34, 35 and 36 interconnecting with passage means and valve means formed in the housing means 21 and being respectively generally indicated by the reference numerals 37 and 38.

The passage means 37 of the relay construction 20 includes all of the chambers and internal passages of the housing means 21 and defines a stationary valve seat 39 in the housing means 21 which is adapted to be opened and closed by a poppet valve member 40 normally urged to its closed position against the valve seat 39 by a compression spring 41 having one end 42 bearing against the poppet valve member 40 and the other end 43 hearing against a housing part 44 held stationary in the housing part 25. The housing part 44 has a passage 45 passing therethrough and loosely receiving a stem portion 46 of the poppet valve member 40 so as to guide axial movement thereof relative to the valve seat 39.

The poppet valve member 40 is disposed within a chamber 47 formed in the housing means 21 and being fluidly interconnected by a passage 48 of the passage means 37 to the port 32, the housing part 44 having a suitable passage 49 formed therethrough so that the entire poppet valve member 40 and its stem 46 will be completely surrounded by the fluid pressure in the chamber 47 under certain conditions as will be apparent hereinafter.

The valve seat 39 of the housing means 21 is adapted to fluidly interconnect the chamber 47 with another chamber 50 of the housing means 21 when the valve seat 39 is in an open condition, the chamber 50 being interconnected by the passage 51 of the passage means 37 to the port 35 as illustrated.

The valve means 38 of the relay construction includes a tubular member 52 being secured at its upper end 53 to an end plate means 54 that closes off the upper end 53 of the tubular member 52 and is adapted to be disposed against the flexible diaphragm 29 as illustrated.

The housing means 21 provides two annular sealing means 55 and 56 to seal along the tubular member 52 in axial spaced relation therewith while permitting the tubular member 52 to move axially relative thereto, the sealing means 56 sealing the chamber 50 from another chamber 57 formed in the housing means 21 and being interconnected by a passage 58 of the passage means 37 to the port 33. The other annular sealing means 55 fluid seals the chamber 57 from another chamber 59 formed in the housing means 21 and being interconnected by a passage 60 of the passage means 37 to the port 36.

The chamber 59 is fluid sealed by the diaphragm 29 from another chamber 61 formed in the housing means 21 and defined between the flexible diaphragm 29 and the end plate 23 of the housing means 21. A suitably formed passage 62 of the passage means 37 fluidly interconnects the chamber 61 to the port 34.

The sealing means 56 for the tubular member 52 comprises an annular packing or sealing means 63 received in an annular recess 64' formed in the housing part intermediate the chambers 50 and 57 and being held therein by an annular retaining ring 64 urged toward a shoulder 65 of the housing means 21 by a compression spring 66.

The annular sealing means 55 includes an annular retainer 67 having an annular groove 68 therein receiving an annular packing or sealing means 69, the retainer 67 having an annular flange 70 held against an annular shoulder 71 of the housing 21 by a snap split-ring 72.

The lower end 73 of the tubular member 52 acts as a movable valve seat and is adapted to engage against a resilient upper end 74 of the poppet valve member to have the end 73 closed by the valve member 40 when the movable valve seat 73 is moved downwardly through the valve seat 39 in a manner hereinafter described, the valve seat 73 leading to the interior of the tubular member 52 with the interior of the tubular member 52 being adapted to be fluidly connected to the chamber 57 by opening means 75 formed through the tubular member 52 as illustrated.

The movable valve seat 73 is normally urged to the open condition illustrated in FIG. 1 by a compression spring 76 having one end 77 bearing against the end plate 54 and the other end 78 bearing against the stationary retainer 67 as illustrated whereby the compression spring 76 tends to move the diaphragm 29 in its up condition as illustrated in FIG. 1 and thereby reduce the volume of the chamber 61 as will be apparent hereinafter.

The lower flexible diaphragm 30 separates the chamber 47 from another chamber 79 of the housing means 21 that is defined between the flexible diaphragm 30 and the end plate 27, the chamber 79 being interconnected by a passage 80 of the passage means 37, as well as by a cutout 81 in the flexible gasket 31, to the port 33 and, thus, to the chamber 57 as illustrated.

The flexible diaphragm 30 and its associated chamber 79 are adapted to act as a fluid balancing means for the poppet valve member 40 in a manner hereinafter described whereby when fluid pressure is received in the chamber 79, the side 82 of the flexible diaphragm 30 is urged upwardly by such fluid pressure against the end 83 of the poppet valve member 40 to tend to urge the poppet member 40 toward its closed position against the valve seat 39 for a purpose hereinafter described whereby the force of the fluid in balancing chamber 79 tends to balance the force of any fluid in the chamber 50 tending to move the valve member 40 away from the valve seat 39.

From the above, it can be seen that the relay construction 20 of this invention can be formed from a relatively small number of parts and can be operated as a normally closed relay, as a normally open relay or as a diverting relay in a manner now to be described.

When it is desired to utilize the relay construction 20 of this invention as a normally closed relay, the port 32 is interconnected to a fluid source 84 as illustrated in FIGS. 5 and 6 while the port 35 is interconnected to a fluid operated control device 85. The port 34 is fluidly interconnected to a fluid signal generating device or means 86 while the port 33 is interconnected to vent means 87 which could comprise the atmosphere or a reservoir as desired, the port 36 merely being vented to the atmosphere as illustrated or to another vent means as desired.

However, it is to be understood that the port 36 could be utilized as a canceling port whereby fluid pressure could be directed into port 36 to cancel the effect of signal pressure being directed into signal port 34 as will be apparent hereinafter.

When the relay construction 20 is disposed in the control system in the manner illustrated in FlGS. 5 and 6, it can be seen that when the fluid signal generating means 86 is in its of condition, so that the same is not delivering any fluid pressure signal to the port 34 and, thus, to the chamber 61 of the relay construction 20, the compression spring 76 maintains the movable valve seat 73 in the open condition illustrated and the compression spring 41 maintains the poppet valve member 40 in its closed position against the valve seat 39 whereby the fluid pressure being supplied by the supply means 84 to the port 32 is blocked by the closed valve seat 39 so that the same cannot reach the fluid operated control device which is deactivated by being interconnected to the vent means 87 through the open valve seat 73. Also, the fluid pressure being delivered by the source 84 into the port 32 of the relay construction 21) completely surrounds the poppet valve member 40 to assist the spring 41 in holding the poppet valve member 40 in its closed position, the fluid pressure in the chamber 47 acting against the upper side 82 of the flexible diaphragm 30 to hold the same away from the end 83 of the poppet valve member 40 as illustrated in FIG. 5 as the chamber 79 is interconnected by the passage 80 to the vent means 87 and thereby does not have any fluid pressure therein whereby the fluid pressure in the chamber 47 acts on the end 83 of the valve member 40.

However, when the signal generating device 86 delivers a fluid signal to the port 34 of the relay construction 20, such fluid signal is directed by the passage 62 to the chamber 61 and acts on the diaphragm 29 to move the diaphragm 29 and the tubular member 52 downwardly in opposition to the force of the compression spring 76 in the manner illustrated in FIG. 6 whereby the movable valve seat 73 engages against the poppet valve member 411 and moves the same downwardly in opposition to the force of its compression spring 41 as illustrated in FIG. 6 to not only close the valve seat 73, but to also open the stationary valve seat 39 whereby the fluid source 84 is now interconnected through the open valve seat 39 to the fluid operated control device 85 to operate the same as the closed valve seat 73 disconnects the fluid operated device 85 from the vent means 87.'

When the signal generating device 86 subsequently terminates the signal being directed to the port 34 and causes venting of the port 34 in a manner well known in the art, the subsequent evacuation of the fluid pressure from the chamber 61 permits the compression spring 76 to return the tubular member 52 from the position illustrated in FIG. 6 back to the position illustrated in FIG. 5 whereby the poppet valve 40, under the force of the compression spring 41, is adapted to close against the valve seat 39 while the movable valve seat 73 moves further away from the poppet valve member 40 to cause opening of the movable valve seat 73 in the manner illustrated in FIG. 5. Thus, the fluid source 84 is now disconnected by the closed valve seat 39 from the fluid operated control device 85 and the fluid operated control device 85 is now interconnected to the vent means 87 through the opened valve seat 73 and passage 75 in the tubular member 72 as illustrated whereby the fluid operated device 85 is effectively deactivated.

Therefore, it can be seen that when it is desired for the relay construction 20 to act as a normally closed relay construction, the relay construction 20 merely has the port means 32-35 interconnected in the manner illustrated in FIGS. 5 and 6.

When it is desired to utilize the relay construction 20 to act as a normally open relay construction, the relay construction 20 is interconnected in a system in the manner illustrated in FIGS. 7 and 8.

In particular, the fluid supply 84 is now interconnected to the port 33 while the vent means 87 is interconnected to the port 32, the fluid operated control device 85 and the fluid signal generating means 86 respectively being interconnected to the ports 35 and 34 as illustrated.

Thus, as long as the signal generating means 86 is not delivering a fluid signal to the port 34, no fluid pressure is in the chamber 61 so that the movable valve seat 73 is in the up or open condition as illustrated in FIG.

ill

7 and the poppet valve member 40 is closed against the stationary valve seat 39. Accordingly, the fluid supply 84 is fluidly connected through the opened valve seat 73 to the port 35 and, thus, to the fluid operated control device 85 to operate the same as long as the signal generating means 86 is in the of condition as illustrated in FIG. 7.

It can be seen that if it were not for the fluid balancing diaphragm 30 of this invention, the fluid pressure from the port 33 being delivered through the open valve seat 73 to the fluid operated control device 85,

' when the relay construction 20 is in the condition illustrated in FIG. 7, will act through the valve seat 39 and against the top 74 of the valve member 40 to push the same away from the valve seat 39 in oppositin to the force of the compression spring 41 and thereby cause the fluid supply 84 to be directed to the vent means 87 so that the fluid operated control device 85 could not be operated in the above manner.

However, because the passage and cut out 81 in the gasket 31 fluidly interconnects the supply pressure port 33 to the chamber 79, the fluid pressure in the chamber 79 acts against the under side of the diaphragm 30 and urges the same into engagement with the end 83 of the stem 46 of the poppet valve member 40 to urge the same against the valve seat 39 so that the fluid pressure in chamber 79 balances the pressure action on the top 74 of the valve member 40 whereby the force of the spring 41 is sufficient to maintain the valve member 40 in its closed position against its valve seat 39.

However, when the fluid signal generating means 86 is in the on condition as illustrated in FIG. 8 and thereby delivering fluid pressure to the chamber 61, the fluid pressure in the chamber 61 drives the movable valve seat 73 downwardly in the manner previously described to close the valve seat 73 and open the poppet valve member 40 away from the stationary valve seat 39 whereby the fluid supply 84 is now disconnected from the chamber 50 because of the closed movable valve seat 73 while the chamber 50 is now interconnected to the chamber 47 and, thus, to the vent 87 through the opened valve seat 39 so that the fluid operated control device 85 is interconnected to the vent means 87 and is, thus, deactivated.

Since the area of the upper diaphragm 29 having the fluid pressure being directed by the chamber 61 thereagainst is relatively large, the force provided by the diaphragm 29 in moving the movable valve seat 73 downwardly to open the valve member 40 away from the valve seat 39 fully overcomes not only the force of the compression springs 76 and 41, but also fully overcomes the force of the pressure in the balancing chamber 79 so that the poppet valve member 40 can be readily opened against the pressure in the balancing chamber 79.

Subsequently, when the signal generating device 86 terminates its signal so that the same causes venting of the pressure in the chamber 61 in a manner conventional in the art, the force of the compression springs 76 and 41, as well as the force of the balancing diaphragm 30, moves the poppet valve member 40 and its movable valve seat 73 upwardly until the poppet valve member 40 seats into engagement with the valve seat 39 in the manner illustrated in FIG. 7. The movable valve seat 73 then continues upwardly under the force of the compression spring 76 to open the valve seat 73 7 so that the fluid supply 84 can again be interconnected to the fluid operated control device 85 as illustrated to activate the same.

When it is desired to utilize the relay construction as a diverting relay, the relay construction 20 can be interconnected in the manner illustrated in FIGS. 9 and 10.

In particular, it can be seen in FIGS. 9 and 10 that the fluid supply 84 is now interconnected to the port 35 while a first fluid operated control device 88 is interconnected to the port 33 and a second fluid operated control device 89 is interconnected to the port 32, the signal generating means being interconnected to the port 34 as illustrated. I

With the signal generating means 86 in an of condition thereof so that no fluid pressure is being delivered to the chamber 61, the movable valve seat 73 is in an open. condition as illustrated in FIG. 9 while the poppet valve member 40 is in a closed condition against the valve seat 39. Thus, the fluid supply 84 is interconnected through the open valve seat 73 to the port 33, and, thus, to the first fluid operated control device 88 to operate the same while such fluid pressure supply means 84 is prevented from being interconnected to the second fluid operated control device 89 by the closed valve seat 39, the control device 89, thus, being deactivated as the same can be vented through suitable bleed means thereof in a manner well known in the art.

As previously stated, if the balancing diaphragm ofthis invention was not utilized, the fluid pressure acting on the top.74 of the poppet valve member 40 at the chamber 50 would cause the poppet valve member 40 to be opened against the force of the compression spring 41. However, because fluid pressure is being delivered from the chamber 57 through the passage 80 and cutout 81 to the chamber 79 in the manner previously described, such fluid pressure in the chamber 79 causes the diaphragm 30 to engage against the end 83 of the poppet valve member 40 and urge the same to ward a closed position to thereby balance the force of the pressure tending to open the poppet valve member 40 so that the force of the compression spring 41 is sufficient to maintain the poppet valve member 40 in its closed position against the stationary valve seat 39.

When the signal generating means 86 delivers a fluid signal to the chamber 61, the fluid pressure in the chamber 61 now drives the movable valve seat 73 downwardly to cause the same to be closed by the poppet valve member 40 while moving the. poppet valve member 40 away from the valve seat 39 as illustrated in FIG. 10 so that the fluid supply 84 is now interconnected through the opened valve seat 39 to the second fluid operated control device 89 to operate the same while the closed valve seat 73 now disconnects the fluid supply 84 from the first fluid operated control device 88 so that the same will be deactivated through suitable bleed means thereof in a manner conventional in the art.

When the signal generating means 86 terminates its fluid signal to the chamber 61, the chamber 61 is vented in a manner conventional in the art and the poppet valve member 40 returns to its closed position against its valve seat 39 while the movable valve seat 73 moves to the open condition as illustrated in 39 so that the fluid supply 84 is again interconnected to the first control device 88 while the fluid supply 84 is disconnected from the second control device 89.

In all of the operations of the relay construction 20 as illustrated in FIGS. 5-10, it can be seen that any dash-pot effect created by the chamber 59 of the housing means 21 on the movement of the diaphragm 29 is eliminated by having the chamber 59 continuously interconnected to the atmosphere or other vent means through the port 36.

. However, if the port 36 is to be utilized as a canceling port for any or all of the operations of the relay construction 20 as illustrated in FIGS. 5-10, fluid pressure can be directed into port 36 and, thus, into chamber 59 to act against the underside of the diaphragm 29 and when the force of such canceling pressure in the chamber 59 together with theforce of the spring 76 exceeds the signal pressure in the chamber 61 acting downwardly on the top of the diaphragm 29, the diaphragm 29 and movable valve seat 73 are moved upwardly as illustrated in FIGS. 5, 7 and 9 so that the effect of the signal pressure to port 34 is canceled.

From the above, it can be seen that the relay construction 20 of this invention is readily adapted to automatically act as a normally closed relay, a normally open relay, or as a diverting relay merely depending upon how the fluid supply and other devices are interconnected to the port means thereof without requiring any change in the internal or external structure of the relay construction 20.

Therefore, it can be seen that this invention not only provides an improved relay construction, but also this invention provides improved parts for such relay construction or the like.

While the form of the invention now preferred has been described and illustrated as required by the patent statute, it is to be understood that other forms can be utilized and still come within the scope ofthe appended claims.

What is claimed is:

1. A relay construction comprising a housing having port means, said housing having passage means and valve means interconnecting with said port means, said housing having control means for causing said relay construction to selectively act as a normally closed relay, as a normally open relay or as a diverting relay, said control means comprising a movable valve member, said housing having balancing means for balancing said movable valve member under certain conditions of operation of said relay construction, said balancing means comprising a flexible diaphragm for engaging against said valve member when balancing the same and for being out of contact with said valve member when not balancing said valve member, said housing having means for causing said diaphragm to balance said valve member and for causing said diaphragm not to balance said valve member.

2. A relay construction as set forth in claim 1 wherein said balancing means does not balance said valve member when said relay construction is acting as a normally closed relay.

3. A relay construction as set forth in claim 1 wherein said balancing means balances said valve member when said relay construction is acting as a normally open relay.

4. A relay construction as set forth in claim 1 wherein said balancing means balances said valve member when said relay construction is acting as a diverting relay.

5. A relay construction as set forth in claim 1 wherein said valve means comprises a valve seat that is opened and closed by said valve member, said diaphragm urging said valve member toward said valve seat when said diaphragm is being utilized to balance said valve member.

6. A relay construction as set forth in claim ll wherein said port means comprise first, second, third and fourth ports.

7. A relay construction as set forth in claim 6 wherein said relay construction when acting as a normally closed relay is adapted to have said first port connected to a source of fluid, said fourth port connected to a fluid operated control device, said third port connected to a fluid signal means and said second port connected to vent means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said first and fourth ports when no fluid signal is received at said third port and whereby said valve means interconnects said first port to said fourth port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port.

8. A relay construction as set forth in claim 7 wherein said relay construction when acting as a normally open relay is adapted to have said second port connected to a source of fluid, said fourth port connected to a fluid operated control device, said first port connected to vent means and said third port connected to fluid signal means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said fourth and first ports when no fluid signal is received at said third port and whereby said valve means interconnects said fourth port to said first port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port.

9. A relay construction comprising a housing having port means, said housing having passage means and valve means interconnecting with said port means, said housing having control means for causing said relay construction to selectively act as a normally closed relay, as a normally open relay or as a diverting relay, said port means comprising first, second, third and fourth ports, said relay construction when acting as a normally closed relay being adapted to have said first port connected to a source of fluid, said fourth port connected to a fluid operated control device, said third port connected to a fluid signal means and said second port connected to vent means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said first and fourth ports when no fluid signal is received at said third port and whereby said valve means interconnects said first port to said fourth port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port, said relay construction when acting as a normally open relay being adapted to have said second port connected to a source of fluid, said fourth port connected to a fluid operated control device, said first port connected to vent means and said third port connected to fluid signal means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said fourth and first ports when no fluid signal is received at said third port and whereby said valve means interconnects said fourth port to said first port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port, said relay construction when acting as a diverting relay being adapted to have said fourth port connected to a fluid source, said second port connected to a first fluid operated control device, said third port connected to a fluid signal means and said first port connected to a second fluid operated control device whereby said valve means interconnects said fourth port to said second port while preventing interconnection between said fourth and first ports when no fluid signal is received at said third port and whereby said valve means interconnects said fourth port to said first port while preventing interconnection between said fourth and second ports when a fluid signal is re ceived at said third port.

10. A relay construction as set forth in claim 9 wherein said valve means includes a movable valve member and a valve seat controlled thereby and interconnecting said first and fourth ports together.

11. A relay construction as set forth in claim 10 wherein said control means comprise means for balancing said valve member under certain operating conditions of said relay construction.

12. A relay construction as set forth in claim 11 wherein said control means comprises a flexible diaphragm for engaging against said valve member to balance the same.

13. A relay construction as set forth in claim 12 wherein said housing has a chamber defined in part by one side of said diaphragm whereby fluid pressure in said chamber will tend to cause the other side of said diaphragm to engage said valve member and thereby balance the same.

14. A relay construction as set forth in claim 13 wherein said housing has means interconnecting said second port and said chamber together.

15. A relay construction as set forth in claim 14 wherein said housing has means interconnecting said first port to said other side of said diaphragm.

16. In a relay construction having a housing means provided with passage means and movable valve means for controlling said passage means in accordance with a control signal being directed thereto, the improvement comprising a movable valve member forming part of said movable valve means, and balancing means for balancing said movable valve member under certain conditions of operation of said relay construction, said housing means having a valve seat adapted to be opened and closed by said valve member, said balancing means being adapted to balance said valve member in a direction toward said valve seat, said balancing means comprising a flexible diaphragm, said flexible diaphragm cooperating with said housing means to define a chamber on the side of said diaphragm that is opposite to the side thereof that faces toward said valve member, said housing means having means for directing fluid to said chamber to thereby cause said diaphragm to balance said valve member, said housing means having means to direct fluid to said opposite side of said diaphragm to override said fluid effect in said chamber.

117. A relay construction as set forth in claim 16 wherein said movable valve means further comprises a movable valve seat adapted to move through the first valve seat and engage said valve member to be closed spring means operatively associated with said movable valve seat to tend to move 'the same away from said valve member.

20. A relay construction as set forth in claim 19 wherein said housing means has fluid operated means for acting on said movable valve seat to move the same in opposition to its spring means toward said valve member. 

1. A relay construction comprising a housing having port means, said housing having passage means and valve means interconnecting with said port means, said housing having control means for causing said relay construction to selectively act as a normally closed relay, as a normally open relay or as a diverting relay, said control means comprising a movable valve member, said housing having balancing means for balancing said movable valve member under certain conditions of operation of said relay construction, said balancing means comprising a flexible diaphragm for engaging against said valve member when balancing the same and for being out of contact with said valve member when not balancing said valve member, said housing having means for causing said diaphragm to balance said valve member and for causing said diaphragm not to balance said valve member.
 2. A relay construction as set forth in claim 1 wherein said balancing means does not balance said valve member when said relay construction is acting as a normally closed relay.
 3. A relay construction as set forth in claim 1 wherein said balancing means balances said valve member when said relay construction is acting as a normally open relay.
 4. A relay construction as set forth in claim 1 wherein said balancing means balances said valve member when said relay construction is acting as a diverting relay.
 5. A relay construction as set forth in claim 1 wherein said Valve means comprises a valve seat that is opened and closed by said valve member, said diaphragm urging said valve member toward said valve seat when said diaphragm is being utilized to balance said valve member.
 6. A relay construction as set forth in claim 1 wherein said port means comprise first, second, third and fourth ports.
 7. A relay construction as set forth in claim 6 wherein said relay construction when acting as a normally closed relay is adapted to have said first port connected to a source of fluid, said fourth port connected to a fluid operated control device, said third port connected to a fluid signal means and said second port connected to vent means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said first and fourth ports when no fluid signal is received at said third port and whereby said valve means interconnects said first port to said fourth port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port.
 8. A relay construction as set forth in claim 7 wherein said relay construction when acting as a normally open relay is adapted to have said second port connected to a source of fluid, said fourth port connected to a fluid operated control device, said first port connected to vent means and said third port connected to fluid signal means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said fourth and first ports when no fluid signal is received at said third port and whereby said valve means interconnects said fourth port to said first port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port.
 9. A relay construction comprising a housing having port means, said housing having passage means and valve means interconnecting with said port means, said housing having control means for causing said relay construction to selectively act as a normally closed relay, as a normally open relay or as a diverting relay, said port means comprising first, second, third and fourth ports, said relay construction when acting as a normally closed relay being adapted to have said first port connected to a source of fluid, said fourth port connected to a fluid operated control device, said third port connected to a fluid signal means and said second port connected to vent means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said first and fourth ports when no fluid signal is received at said third port and whereby said valve means interconnects said first port to said fourth port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port, said relay construction when acting as a normally open relay being adapted to have said second port connected to a source of fluid, said fourth port connected to a fluid operated control device, said first port connected to vent means and said third port connected to fluid signal means whereby said valve means interconnects said second port to said fourth port while preventing interconnection between said fourth and first ports when no fluid signal is received at said third port and whereby said valve means interconnects said fourth port to said first port while preventing interconnection between said second and fourth ports when a fluid signal is received at said third port, said relay construction when acting as a diverting relay being adapted to have said fourth port connected to a fluid source, said second port connected to a first fluid operated control device, said third port connected to a fluid signal means and said first port connected to a second fluid operated control device whereby said valve means interconnects said fourth port to said second port while preventing interconnection between said fourth and first ports when no flUid signal is received at said third port and whereby said valve means interconnects said fourth port to said first port while preventing interconnection between said fourth and second ports when a fluid signal is received at said third port.
 10. A relay construction as set forth in claim 9 wherein said valve means includes a movable valve member and a valve seat controlled thereby and interconnecting said first and fourth ports together.
 11. A relay construction as set forth in claim 10 wherein said control means comprise means for balancing said valve member under certain operating conditions of said relay construction.
 12. A relay construction as set forth in claim 11 wherein said control means comprises a flexible diaphragm for engaging against said valve member to balance the same.
 13. A relay construction as set forth in claim 12 wherein said housing has a chamber defined in part by one side of said diaphragm whereby fluid pressure in said chamber will tend to cause the other side of said diaphragm to engage said valve member and thereby balance the same.
 14. A relay construction as set forth in claim 13 wherein said housing has means interconnecting said second port and said chamber together.
 15. A relay construction as set forth in claim 14 wherein said housing has means interconnecting said first port to said other side of said diaphragm.
 16. In a relay construction having a housing means provided with passage means and movable valve means for controlling said passage means in accordance with a control signal being directed thereto, the improvement comprising a movable valve member forming part of said movable valve means, and balancing means for balancing said movable valve member under certain conditions of operation of said relay construction, said housing means having a valve seat adapted to be opened and closed by said valve member, said balancing means being adapted to balance said valve member in a direction toward said valve seat, said balancing means comprising a flexible diaphragm, said flexible diaphragm cooperating with said housing means to define a chamber on the side of said diaphragm that is opposite to the side thereof that faces toward said valve member, said housing means having means for directing fluid to said chamber to thereby cause said diaphragm to balance said valve member, said housing means having means to direct fluid to said opposite side of said diaphragm to override said fluid effect in said chamber.
 17. A relay construction as set forth in claim 16 wherein said movable valve means further comprises a movable valve seat adapted to move through the first valve seat and engage said valve member to be closed thereby while opening said valve member away from its respective valve seat.
 18. A relay construction as set forth in claim 17 wherein said movable valve means further comprises a spring means operatively associated with said valve member to tend to move said valve member toward its respective valve seat.
 19. A relay construction as set forth in claim 17 wherein said movable valve means further comprises a spring means operatively associated with said movable valve seat to tend to move the same away from said valve member.
 20. A relay construction as set forth in claim 19 wherein said housing means has fluid operated means for acting on said movable valve seat to move the same in opposition to its spring means toward said valve member. 